Re: One More LO&S

John Stutz


The LO&S vertical drive shaft, between body and truck, is rare because it is mechanically unsound: There is nothing between body and truck to sustain the drive's torque reaction, so the truck's wheels' flanges must carry that load.  The builders got away with it in the LO&S car because its tractive force is very light.  But pulling a trailer might have been chancy, regarding derailment of the power truck. 

Logging modelers may remember that some of Westside Models'  HO Shays used a mechanically similar vertical drive shaft between the body and the powered truck.  Under high tractive load that truck tends to twist itself off of the rails.  The bigger the Shay, the worse the problem.  I once owned one of Dick's HOn3 "Hassenger" Shays, nominally a 90-D but actually a C&O or N&W 150-D on NG trucks.  It came with an aftermarket brace for the powered truck, to restrain that truck's pivoting.  Later Westside Shays used a redesigned drive, with a longitudinal shaft between body and truck, where the torque reaction is easily restrained by the bolsters.

American Hoist & Derrick's ditchers used a vertical shaft through the rotating platform's pivot to drive the trucks.  But there is a gearbox under the car body, and final drive from the body to the trucks is via either longitudinal shafts or flexible chains.  The operator also had to restrain the platform's rotation when powering the trucks.

Kemtron or Grandt once offered (ca 1970?) an On3 Shay drive with a vertical motor.  That design worked because the motor was mounted on the truck, with a rigid path to carry torque reaction back to the motor shell. 

John Stutz

On December 4, 2020 8:07 PM climax@... wrote:

George:    ....  The drive system on the LO&S intrigues me though.  Where can I get more information on it.  Do you have drawings or what?  I am working on full filling the last Certificate of Achievement of the 11 in the NMRA, Motive Power.  I have the other 10 and actually received the MMR status back in 1993, #200.  I have one rail bus I built and this will be #2 of the three required.  ....

David Barron
Winter Graden, FL

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